Public Release: 8-Oct-2013
Aircraft noise linked to higher rates of heart disease and stroke near London Heathrow Airport

Risks of hospital admissions and deaths from stroke, heart and circulatory disease are higher in areas with high levels of aircraft noise, a study has found.

Researchers at Imperial College London and King's College London compared data on day- and night-time aircraft noise with hospital admissions and mortality rates among a population of 3.6 million people living near Heathrow airport.

The risks were around 10 to 20 per cent higher in areas with highest levels of aircraft noise compared with the areas with least noise.

The findings are published in the British Medical Journal.

Previous research has found links between living in a noisy environment and risk of high blood pressure, but few studies have looked at stroke, heart disease and circulatory disease.

The new findings raise the possibility that aircraft noise may be a contributing factor to these conditions, but the researchers say more work is needed to establish the exact relationship between noise and ill health.

Dr Anna Hansell, from the School of Public Health at Imperial, the lead author of the study said: "These findings suggest a possible link between high levels of aircraft noise and risk of heart disease and stroke. The exact role that noise exposure may play in ill health is not well established. However, it is plausible that it might be contributing, for example by raising blood pressure or by disturbing people's sleep. The relative importance of daytime and night-time noise also needs to be investigated further."

Professor Paul Elliott, the senior author of the study and director of the UK Small Area Health Statistics Unit and MRC-PHE Centre for Environment and Health where the study was conducted, added: "From this type of study, we can't say for certain that aircraft noise is responsible for the increased heart disease and stroke risk in these communities as there are other possible explanations.

"It's worth bearing in mind that there are many other factors that are known to have important influences on an individual's risk of heart disease and stroke , such as diet, smoking, lack of exercise and medical conditions such as raised blood pressure and diabetes. However, our study does raise important questions about the potential role of noise on cardiovascular health, which needs further study"

The study covered 12 London boroughs and nine districts outside of London where aircraft noise exceeds 50 decibels - about the volume of a normal conversation in a quiet room.

The whole study area was divided into 12,110 small areas, each with a population of around 300. For each small area, the researchers looked at noise levels from 2001, provided by the Civil Aviation Authority, and hospital admissions and deaths from 2001-2005.

The researchers also considered other factors in those areas that have been linked to heart disease rates, like social deprivation, ethnic composition, road traffic noise, air pollution and lung cancer rates - a proxy for the prevalence of smoking.

After adjusting for these factors, South Asian ethnicity - which is associated with higher risks of heart disease - was found to account for part of the association between heart disease admissions and noise levels, as many areas with the most noise also have large South Asian populations.

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The centre where the work was carried out is funded by Public Health England and the Medical Research Council.

2. The area included in the study comprised the London boroughs of Hillingdon, Hounslow, Ealing, Brent, Hammersmith and Fulham, Kensington and Chelsea, Westminster, Richmond upon Thames, Kingston upon Thames, Wandsworth, Lambeth and Southwark; and nine districts to the west of London: Windsor and Maidenhead, Slough, Spelthorne, Wokingham, Elmbridge, Bracknell Forest, Wycombe, Runnymede and South Bucks.

3. About Imperial College London

Consistently rated amongst the world's best universities, Imperial College London is a science-based institution with a reputation for excellence in teaching and research that attracts 14,000 students and 6,000 staff of the highest international quality. Innovative research at the College explores the interface between science, medicine, engineering and business, delivering practical solutions that improve quality of life and the environment - underpinned by a dynamic enterprise culture.

Since its foundation in 1907, Imperial's contributions to society have included the discovery of penicillin, the development of holography and the foundations of fibre optics. This commitment to the application of research for the benefit of all continues today, with current focuses including interdisciplinary collaborations to improve global health, tackle climate change, develop sustainable sources of energy and address security challenges.

In 2007, Imperial College London and Imperial College Healthcare NHS Trust formed the UK's first Academic Health Science Centre. This unique partnership aims to improve the quality of life of patients and populations by taking new discoveries and translating them into new therapies as quickly as possible.

King's College London is one of the top 20 universities in the world (2013/14 QS World University Rankings), and the fourth oldest in England. A research-led university based in the heart of London, King's has more than 25,000 students (of whom more than 10,000 are graduate students) from nearly 140 countries, and some 6,500 employees. King's is in the second phase of a £1 billion redevelopment programme which is transforming its estate.

King's has an outstanding reputation for providing world-class teaching and cutting-edge research. In the 2008 Research Assessment Exercise for British universities, 23 departments were ranked in the top quartile of British universities; over half of our academic staff work in departments that are in the top 10 per cent in the UK in their field and can thus be classed as world leading. The College is in the top seven UK universities for research earnings and has an overall annual income of nearly £450 million.

King's has a particularly distinguished reputation in the humanities, law, the sciences (including a wide range of health areas such as psychiatry, medicine, nursing and dentistry) and social sciences including international affairs. It has played a major role in many of the advances that have shaped modern life, such as the discovery of the structure of DNA and research that led to the development of radio, television, mobile phones and radar.

King's College London and Guy's and St Thomas', King's College Hospital and South London and Maudsley NHS Foundation Trusts are part of King's Health Partners. King's Health Partners Academic Health Sciences Centre (AHSC) is a pioneering global collaboration between one of the world's leading research-led universities and three of London's most successful NHS Foundation Trusts, including leading teaching hospitals and comprehensive mental health services. For more information, visit: http://www.kingshealthpartners.org.

5. About the Medical Research Council

The Medical Research Council has been at the forefront of scientific discovery to improve human health. Founded in 1913 to tackle tuberculosis, the MRC now invests taxpayers' money in some of the best medical research in the world across every area of health. Twenty-nine MRC-funded researchers have won Nobel prizes in a wide range of disciplines, and MRC scientists have been behind such diverse discoveries as vitamins, the structure of DNA and the link between smoking and cancer, as well as achievements such as pioneering the use of randomised controlled trials, the invention of MRI scanning, and the development of a group of antibodies used in the making of some of the most successful drugs ever developed. Today, MRC-funded scientists tackle some of the greatest health problems facing humanity in the 21st century, from the rising tide of chronic diseases associated with ageing to the threats posed by rapidly mutating micro-organisms. http://www.mrc.ac.uk

The MRC Centenary Timeline chronicles 100 years of life-changing discoveries and shows how our research has had a lasting influence on healthcare and wellbeing in the UK and globally, right up to the present day. http://www.centenary.mrc.ac.uk

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